An hf superstructure discone antenna

ABSTRACT

A superstructure discone HF antenna comprising a vertically oriented ship&#39;&#39;s superstructure and a discone antenna connected to and rigidly supported and mounted upon the top thereof to form a unitary radiating structure. By using a self-supporting superstructure as an integral component of the antenna, the number of possible HF parasitic radiators is reduced and limited topside space available on naval ships is more efficiently utilized.

UnitedStates Patent [l5] 3,671,971 Goodbody 1 June 20, 1972 s4j HF SUPERSTRUCTURE DISCONE 3.189.906 6/1965 Kulik et a]. 343 10 ANTENNA Primary Examiner-Eli Lieberman [72] Inventor: Richard L. Goodbody, San Diego, Calif. At!0rney-R. S. Sciascia. George J. Rubens and J. W. [73] Assignee: The United 7 States oi America Is Me n IQPIQSQIIHI by the Secretary 0' the NIV) 57 W [22] Filed: Mmh 1971 A superstructure discone HF antenna comprising a vertically n APPLNOJ 128,787 oriented ship's superstructure and a discone antenna connected to and rigidly supported and mounted upon the top thereof to form a unitary radiating structure. By using a self- [52] US. 43/846 supporting superstructure as an integral component of the an- [Sl] lnt.Cl....., .L ..l-l0lq 1/34 tenna, the number of possible HF parasitic radiators is [58] Field of Search ..343/709, H0, 773, 846, 908 reduced and limited topside space available on naval ships is Y more efiiciently utilized. i [56] References Cited 4c] I ,lmwing Figure UNITED STATES PATENTS 2,704,811 3/1955 Walters ..343/7l0 2 v iii- 26o 1 51 48 2 I lea EU I I 50 I l l iii PATENTEnJuazo m2 INVENTOR. RICHARD L.GOODBODY ATTORNEYS 1 :AN-l-IF SUPERSTRUCTUREDISCONE ANTENNA STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmentaLpurposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Modern sophisticated naval ships include increasing numbers of electronic equipments and mechanical structures which must be located on the deck of ships. As more and more equipment and structures are required the availability of topside space necessarily becomes critical, consequently it has radiation pattern control on most ships. Consequently it is an object of the present invention to disclose the concept for using a selfsupporting superstructure on a ship as an integral component of a unitary HF antenna which can be used in a limited space environment on a ship's deck.

SUMMARY OF THE INVENTION A unitary, self-supporting superstructure discone HF anten- I na is'disclosed. The antenna comprises a vertically oriented superstructure having a selectively predetermined geometrical configuration upon which is mounted a discone antenna. The discone antenna which is electrically connected to the superstructure comprises a conically shaped component, a horizontally :disposed disc, and a shunting stub consisting of two concentric hollow cylinders having a selectively predetermined length and a diameter ratio with respect to each other to thereby provide a shunt reactance which will allow the antenna to be matched to, for example, a 3:1 VSWR over approximately a 2 to 5.6 MHz frequency range. The superstructure can comprise any of several superstructures typically found on naval ships whereby. the antenna disclosed herein can be used to advantage on ship decks wherespace requirements are critical. Other HF radiators can be mounted on or around the surface of the superstructure as has been done in the prior art.

OBJECTS OF THE INVENTION It is the primary object of the present invention to provide a antenna 14 essentially comprises a superstructure 16 of the type non-nally found on naval ships. The superstructure, which has a conductive surface, can have any of several geometrical configurations; in the preferred embodiment, an octagonal shaped superstructure 16 is shown. Electrically and mechanically connected to and rigidly mounted upon the top of the superstructure 16 is a discone antenna 18 which includes a disc 20, as is well known to those skilled in the art. In the FIGURE,

a conventional conical antenna 22 having a trussed mast is shown mounted upon the superstructure discone antenna 14 to achieve a dual band HF capability. In the FIGURE, the water level comprises the preferred ground plane.

It should be appreciated that the entire volume of the superstructure 16 can be utilized as access, equipment, living, or operating space. For example, superstructure 16 includes a plurality of bridges 16a having bridge windows 16b. The bridges'l6a can be utilized by the ships personnel to perform their required daily functions.

The upper structure 18 is connected to the lower structure by means of an impedance matching shunting stub 24 which broadband HF antenna which includes a ship superstructure as an integral component thereof.

It is another object of the present invention to provide a superstructure discone antenna which can be used effectively in a limited space environment on a naval ship deck.

It is another object of the present invention to provide a superstructure discone antenna having improved radiation pattern characteristics achieved by reducing the number of mechanical structures acting as major parasitic radiators in the HF range.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a simplified front-view of a naval. ship having mounted upon the deck thereof broadband HF antenna embodying the present inventive concept.

DESCRIPTION OF THE PREFERRED EMBODIMENT The FIGURE is a simplified front-view of a naval ship 10 having mounted upon the deck 12 thereof broadband HF antenna 14 embodying the present inventive concept. The HF comprises two concentric hollow cylinders 26a and 26b. The shunting stub has an electrically predetermined length, and the ratio of the diameters of the cylinders 26a and 26b is likewise a selectively predetermined value whereby the characteristic impedance of the shunt stub which appears in parallel across the superstructure antenna can be made equal to a value which, for example, will allow a series capacitor to match the antenna 14 to a 3:1 VSWR over a 2 to 5.6 MHz range. Likewise the conical angle 0 of the conical section 18 of the discone antenna is critical in that is used to determine the characteristic impedance of the entire antenna structure 14. The combined impedance effect of the superstructure 16 and the shunt stub 24 determines the impedance seen at the termination 40.

v The upper portion of the shunting stub 28 located between the conical section 18 and the disc 20 comprises an insulator portion 28. Mounted symmetrically on the top of insulator 28 is a support platform 30 from which a plurality of radials 32 which comprise the disc 20 radiate in a symmetrical manner. In the preferred embodiment sixteen radials are utilized.

Sending apparatus 34 are shown located in a bridge 16a. The sending apparatus can comprise transmitter or receiver means having coaxial cables 36 and 38. The cable 36 is shown connected between the sending apparatus 34 and a coaxial termination 40, which is used to feed the discone antenna at the energy feedpoint 42. Cable 38 is used when a conical-antenna 22 as shown is used to achieve a dual band capability. In this instance, cable 38 would be routed through the center of the shunting stub 24 up to the energy feedpoint of the conical antenna 22 (not shown).

Each of the 16 radials 32 of the disc 20 are terminated in a SO-ohm resistor 44 from which a conductor wire 46 is connected to an insulator 48. Guy wires 50 or rope of a non-conductive material are connected between each insulator 48 and the structure 16 to thereby support and maintain the wires 46 in a selectively predetermined configuration.

At the lower portion of the shunting stub 24, the inner and the outer cylinders 26a and 26b, respectively, are both electrically and mechanically connected to the superstructure 16 which, as previously mentioned, comprises a conductive surface, as does the conical section 18. At the upper portion of the shunting stub, the inner cylinder 26a is electrically and mechanically connected to the disc 20 and the outer cylinder 26b is mechanically, but not electrically, connected to the disc by the insulator 28 which is also mechanically connected to Experimentation has shown that by means of conventional exiting multi-couplers and multi-coupler techniques, the composite structure 14, including the conical antenna 22 can provide simultaneous operation of up to as many as 16 transmitters and forty receivers, for example, in the 2 to MHz band. Furthermore the single structure antenna 14 can be installed on a variety of ships wherein the superstructure can also perform those functions normally required of ships superstructures. This antenna thus comprises a major contribution to ship space utilization in terms of efficient use of topside space and especially in the reduction of parasitic radiators. Consequently it can be appreciated that an entire large superstructure can be made into a broadband HF antenna on which other radiators such as those for radar functions can be mounted in a concentric or co-linear manner on the surface of the superstructure (not shown). This capability to support these other radiators thereby eliminates much of the antenna blockage which occurs on existing ships due to the presence of platforms and equipments.

The conducting surfaces of the superstructure can be formed of electrically conducting solid sheets, welded pipe, or wires spaced at suitable intervals depending on mechanical requirements and upon requirements for weather-tight internal spaces.

The desired characteristic impedance match as previously mentioned is obtained by selectively predetennining the dimensions of the shunt stub and the conical angle 0. The diameter of the disc and the overall height of the structure are determined in part by the desired low-frequency response.

The superstructure 16 itself can comprise either a rectangular, pyramidical, or cylindrical, or conical geometrical configuration; however the cylindrical conical shape has been found to be optimum for overall symmetry. The conical shape is shown distorted in the figure to accommodate other functions such as windows for the bridges. Furthermore equipment such as conformal radar arrays and platforms can be easily installed external to the conducting surfaces, although this capability is limited by the tolerance of discontinuities resulting in impedance perturbation.

The conical antenna 22 located above the disc is not a critical part of the discone superstructure concept, however it is shown in the figure to show how easily the present invention could be modified to provide a dual band HF capability within a unitary structure and without requiring more of the critical space topside of the ship. Thus it can be appreciated that a new and novel combined function HF antenna for use on topside ship environments where space is critical and including as an integral component thereof, a ship's superstructure has been disclosed.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. it is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is: 1. An HF antenna for use in limited space environments on naval ship decks comprising:

a superstructure having a selectively predetermined configuration and an electrically conductive surface; discone antenna rigidly mounted and supported upon the top of said superstructure and being electrically connected to said superstructure by means of a shunt stub extending symmetrically through said discone antenna and a selectively predetermined length of said superstructure, said discone antenna having an electrically conductive surface also. 2. The apparatus of claim 1 wherein said discone antenna comprises:

a conical portion mounted atop of said superstructure; an insulator portion at the top thereof, and a disc connected at the top of said insulator in a symmetrical manner with respect to said insulator, said insulator being symmetrically disposed about said shunt stub. 3. The apparatus of claim 1 wherein said shunt stub comprises:

two hollow concentric cylinders symmetrically disposed within each other and about the center of said superstructure.

4. A dual-band HF antenna for use on decks of naval ships compnsrng:

a superstructure having a predetermined geometrical configuration;

a discone antenna mounted and rigidly connected to said superstructure by means of a shunt stub extending therebetween; and

a conical antenna having a trussed mast mounted atop said discone antenna. 

1. An HF antenna for use in limited space environments on naval ship decks comprIsing: a superstructure having a selectively predetermined configuration and an electrically conductive surface; discone antenna rigidly mounted and supported upon the top of said superstructure and being electrically connected to said superstructure by means of a shunt stub extending symmetrically through said discone antenna and a selectively predetermined length of said superstructure, said discone antenna having an electrically conductive surface also.
 2. The apparatus of claim 1 wherein said discone antenna comprises: a conical portion mounted atop of said superstructure; an insulator portion at the top thereof, and a disc connected at the top of said insulator in a symmetrical manner with respect to said insulator, said insulator being symmetrically disposed about said shunt stub.
 3. The apparatus of claim 1 wherein said shunt stub comprises: two hollow concentric cylinders symmetrically disposed within each other and about the center of said superstructure.
 4. A dual-band HF antenna for use on decks of naval ships comprising: a superstructure having a predetermined geometrical configuration; a discone antenna mounted and rigidly connected to said superstructure by means of a shunt stub extending therebetween; and a conical antenna having a trussed mast mounted atop said discone antenna. 